Drywall Calculator

Divide the total wall and ceiling area by one sheet’s area, then add waste. A 12 × 16 ft room with 8 ft ceilings has about 448 sq ft of wall plus 192 sq ft of ceiling — 640 sq ft (59 m²). In 4 × 8 ft sheets (32 sq ft) that is 20 sheets before waste, so order about 22 with 10%. The calculator totals the walls, ceiling and openings for you.

Installed drywall typically runs about $1.50–$3.50 per square foot including materials and labor, depending on ceiling height, finish level and region. Enter an installation rate per square foot (and/or a price per sheet) and the calculator shows materials, labor and the total. For that 640 sq ft room at $2.00 per sq ft, the estimate is about $1,280.

For taping plus a standard smooth (Level 4) finish, budget roughly a 4.5-gallon (61 lb / 28 kg) box of all-purpose compound per 450–500 sq ft, and about 0.4 linear feet of tape per square foot of board. The calculator estimates both from your board area — a skim (Level 5) or textured finish uses more, so round up.

About one screw per square foot of drywall — roughly 32 screws per 4 × 8 ft sheet at 16 in (400 mm) framing, screwing the field every 12 in and edges every 8 in. The calculator works it out from the board area, so a 640 sq ft job needs on the order of 640–700 screws.

Longer 4 × 12 ft (or 1.2 × 3.0 m) sheets mean fewer butt joints to tape and a flatter wall, which saves finishing time — choose them if you can handle and lift them. Shorter 4 × 8 ft sheets are easier to carry in tight spaces. Pick your sheet size in the calculator and the sheet count updates.